Metallic electrode pairs with angstrom or nano-scale gap play a key role in studying the electron transport in molecular electronic and nano-electronic devices. Here we report a novel method of electrochemical etching...Metallic electrode pairs with angstrom or nano-scale gap play a key role in studying the electron transport in molecular electronic and nano-electronic devices. Here we report a novel method of electrochemical etching to prepare gold electrode pairs. By adjusting the parameter of the homemade feedback loop and the etching voltage,a series of electrode pairs with different sizes of gap were fabricated. The process is simple and dispenses with special equipments. This method also has the potential for fabricating other metallic electrode pair with a controlled gap distance.展开更多
The core-shell Fe2O3@Au particle with spindle morphology were synthesized by three steps.The mean size of the core-shell paricles was about 500 nm by 85 nm.The final single separated spindle particles were attached on...The core-shell Fe2O3@Au particle with spindle morphology were synthesized by three steps.The mean size of the core-shell paricles was about 500 nm by 85 nm.The final single separated spindle particles were attached onto Si substrates.The thiophenol(TP) was served as probe molecule to investigate the pola-rized dependent surface-enhanced Raman scattering(SERS) from single particle.Dramatic variations in SERS intensity was observed when the single core-shell particle was oriented at different angles relative to the polarization of excitation laser.The maximum SERS intensity was detected for TP absorbed on the anisotropic particle which was in the polarization direction parallel to the long axis of the particle,while the minimum intensity was detected at the direction of the incident field that is perpendicular to the long axis of the particle.Our preliminary results provided useful way for obtaining deeper insight to the SERS mechanism.展开更多
James Martin在20世纪90年代初在系统功能语言学的基础上提出了评价系统(Appraisal Systems)的理论,评价理论是一种研究语言的人际功能的理论,包括:介入、态度、级差等子系统。自创立以来,对话语分析理论的发展起了一定的推动作用。文...James Martin在20世纪90年代初在系统功能语言学的基础上提出了评价系统(Appraisal Systems)的理论,评价理论是一种研究语言的人际功能的理论,包括:介入、态度、级差等子系统。自创立以来,对话语分析理论的发展起了一定的推动作用。文章以辩论赛中冲突话语为语料基础,用评价理论来进行分析。展开更多
文摘Metallic electrode pairs with angstrom or nano-scale gap play a key role in studying the electron transport in molecular electronic and nano-electronic devices. Here we report a novel method of electrochemical etching to prepare gold electrode pairs. By adjusting the parameter of the homemade feedback loop and the etching voltage,a series of electrode pairs with different sizes of gap were fabricated. The process is simple and dispenses with special equipments. This method also has the potential for fabricating other metallic electrode pair with a controlled gap distance.
文摘The core-shell Fe2O3@Au particle with spindle morphology were synthesized by three steps.The mean size of the core-shell paricles was about 500 nm by 85 nm.The final single separated spindle particles were attached onto Si substrates.The thiophenol(TP) was served as probe molecule to investigate the pola-rized dependent surface-enhanced Raman scattering(SERS) from single particle.Dramatic variations in SERS intensity was observed when the single core-shell particle was oriented at different angles relative to the polarization of excitation laser.The maximum SERS intensity was detected for TP absorbed on the anisotropic particle which was in the polarization direction parallel to the long axis of the particle,while the minimum intensity was detected at the direction of the incident field that is perpendicular to the long axis of the particle.Our preliminary results provided useful way for obtaining deeper insight to the SERS mechanism.
